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Sustainability

· 6 checks — CO2 emissions, green hosting, repeat-visit weight, carbon budget, and transfer efficiency rolled into one auditable list.
SCORE
72
GRADE
C
FIX
2
REVIEW
1
PASS
3
INFO
0
Device:
Mobile Desktop
Checks
6
3 PASS 1 REVIEW 2 FIX
D
Green Hosting
Action
Unknown
FIX
Unknown
Info::
Hosting provider could not be identified
Without knowing the provider, we cannot determine their energy sourcing. Check with your hosting provider about their renewable energy commitments.
Info::
Green hosting status based on known provider commitments
Green hosting detection uses a curated database of provider renewable energy commitments. This is not a real-time verification. For authoritative checks, visit thegreenwebfoundation.org.
Green HostingUnable to Determine
Hosting Not identified✗CDN Not identified✗

Based on known provider commitments. Verify at thegreenwebfoundation.org

D
Transfer Efficiency
Action
47% efficient
FIX
47% efficient
Critical::
Transfer efficiency: 47%
An estimated 524 KB (53%) could be eliminated: 0 KB via better compression, 0 KB via modern image formats, 524 KB of unused JavaScript. This wasted data produces 0.14g of unnecessary CO2 per page view.
47% efficient

Total waste: 524 KB (53% of page weight)

Unused JS 524 KB

0.14g unnecessary CO2 per visit

Actual transfer 983 KB
Theoretical minimum 458 KB
Potential savings 524 KB (0.14g CO2)

See Deep Analysis sections above for specific optimizations.

C
Green Hosting
Action
Whether the site is served from green-energy infrastructure
REVIEW

Green Hosting

No green hosting detected

A
CO2 Per Page Load
0.27g CO2 per view
PASS
0.27g CO2 per view
Info::
0.27g CO2 per page view
This page transfers 1.0 MB, producing an estimated 0.27g of CO2 per visit using the Sustainable Web Design model (v4). Breakdown: data center 0.05g, network 0.05g, end-user device 0.17g.
Got: 0.27g CO2 Expected: < 0.50g (sustainability target)
Info::
At 10,000 monthly views: 32.6 kg CO2/year
With 10,000 page views per month, this page would generate approximately 32.6 kg of CO2 annually — equivalent to charging 4078 smartphones.

0.27g

Carbon Footprint per page view

✓ Below sustainability target (0.50g)

Cleaner than 83% of websites

Sustainable Web Design model v4 · Page size: 1.0 MB

Your site
0.27g
Top 10%
0.20g
Target
0.50g
Median website
0.60g

Energy Breakdown

Data center
0.05g
Network
0.05g
End-user device
0.17g
At 10,000 monthly views: Monthly: 2.7 kg · Annual: 32.6 kg · ≈ 4078 smartphone charges
A+
Repeat Visit Weight
100% cached
PASS
100% cached
Info::
100% reduction on repeat visits
Returning visitors download only 1 KB (vs 983 KB first visit). 49 of 50 resources are served from browser cache, saving 0.27g CO2 per repeat visit.
Info::
Repeat visit: 0.00g CO2 (first visit: 0.27g)
First visit
983 KB
Repeat visit
1 KB

100% reduction on repeat visits

Saving 0.27g CO2 per returning visitor

49 resources served from cache · 1 resources re-downloaded

A
Carbon Budget
17th percentile
PASS
17th percentile
Info::
0.27g CO2 — below the sustainability target of 0.50g
Cleaner than an estimated 83% of websites analyzed. This page meets the Web Sustainability Guidelines target.
Info::
Estimated 17th percentile
Compared to: top 10% = 0.20g, target = 0.50g, median = 0.60g per page view.
Top 10%
Target
Median website

0.27g

17th percentile

Cleaner than 83% of websites

✓ Below the Web Sustainability Guidelines target

vs Median 55% cleaner ✓
vs Target 46% cleaner ✓
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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